Section 134.304 - Commencement of appeals from size determinations and NAICS code designations(a) Size appeals must be filed within 15 calendar days after receipt of the formal size determination.(b) NAICS code appeals must be filed within 10 calendar days after issuance of the solicitation, or amendment to the solicitation affecting the NAICS code or size standard. However, SBA may file a NAICS code appeal at any time before offers or bids are due.(c) An untimely appeal will be dismissed. 76 FR 5685 , Feb. 2, 2011